class 3 "Earth History & Change"

habitable zone

a comfy distance from its parent star, and has a combination of qualities that make it ideal for life.

Milankovitch cycles

Changes in the shape earth's orbit and tilt that cause glacial periods and interglacial periods.

Eccentricity of Earth's orbit

one of the forces behind climate cycles; sometimes the orbit is nearly circular, sometimes elliptical (100,000 year cycle)

Obliquity (of Earth)

The tilt of the Earth's axis (41,000 year cycle)

precession (of Earth)

the slow, conical motion of Earth's axis of rotation caused principally by the gravitational pull between Vega and the North Star (23,000 year cycle)

how many eons has Earths 4.6-billion-year history gone through?

4 eons.

name of Fourth most recent Earth eon?

Phanerozoic (544MYA-Present)

How did the Phanerozoic eon start?

began with the "Cambrian explosion" (~540-520 MYA) of complex new plants, animals, and fungi.

How many times has Earth experienced mass extinctions, excluding the one happening right now?

5 mass extinctions

Pleistocene epoch

Beginning around 2.5 MYA, the rise of mammals and featured a series of at least 11 major ice ages and interglacial periods.

When did anatomically modern humans appear?

around 300,000 years ago

anatomically modern humans

One of several closely related primate species, they (we) almost went extinct several times.

where did Humans emerge from and when?

from Africa at least 70,000 years ago

What started the 6th mass extinction?

great migration of humans beginning around 50 KYA

Early Humans

paleolithic hunter-gatherers that acquired the use of fire, engaged in horticulture, and hunted wild game.

The word "paleolithic" means?

people that lived fromabout 2.5 million to10,000 years ago, aperiod that includesaround 99 percent ofhuman history

What is the Holocene Epoch?

The current interglacial phase beginning around 12,000 years ago.

What significant social development occurred during the Holocene Epoch?

The emergence of diverse new cultures.

What were Paleolithic hunter-gatherers and sedentary indigenous societies known for ?

profoundly shaped their surroundings over long periods of time.

Anthropocene Epoch

the period in earth history when humans have come to dominate global geological, ecological, and climatological processes (age of humans)

The current consensus place Anthropocene beginning in

1945 with the first nuclear explosion and at the beginning of the Great Acceleration!!!

What is The Great Acceleration?

refers to the period from World War II to the present, during which human population and economic activities grew at a much greater rate than ever before.

What has The Great Acceleration amplified?

Human impacts on nature.

What type of changes has The Great Acceleration caused in earth systems?

Large scale changes.

Examples of human amplifications during the Great Acceleration?

population and economic growth, extraction of natural resources, land use and land cover change, biodiversity loss